DE2806545A1 - COLLECTOR ARRANGEMENT FOR A SOLAR ENERGY HEATING SYSTEM - Google Patents

Description

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Hans-Ulrich Bogatzki, Zurich

Collector arrangement for a solar energy heating system

The present invention relates to a collector arrangement for a solar energy heating system, in which a plurality of collector elements cooperate with, the flow of a heat exchange medium serving tubes.

It is considered certain that the technically feasible from today's perspective, fossil fuels such as coal, crude oil, oil sand, oil shale and natural gas are only available in limited quantities stand. This is especially true for the current main energy source, petroleum. Even with the inclusion of new ones

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Find sites are expected to be the oil stocks in about 50 years will be exhausted. Some internationally recognized research institutes even produce far less inexpensive ones Forecasts. Even these very pessimistic forecasts should not hide the fact that they were made much earlier the shortage of crude oil will lead to considerable price increases in accordance with the laws of supply and demand. The effects of such price increases on our economy could be seen clearly enough after the last oil shock will.

That is why people around the world are looking for new, independent sources of energy. Primary goal of this effort it is' the greatest possible number of substitution energy sources and wherever possible to use them instead of crude oil.

Worldwide statistics show that a considerable amount of heating is used especially for heating purposes Part of the petroleum is consumed.

But it is precisely here that solar energy is ideal Substitution energy. In addition to the fact that this energy is free and in unlimited quantities at human discretion is available, this form of energy is particularly distinctive

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characterized by their pronounced environmental friendliness. Another big advantage is the decentralized usage option to watch. On the other hand, it should be noted that this energy is only used during the day and sometimes only when it is exposed to direct sunlight is to be exploited. It should also be taken into account that solar energy has only a relatively low intensity. This is particularly true when the sky is overcast, when only the significantly small amount of diffuse radiation can be used.

For the use of solar energy for heating purposes, some systems have already become known that also consist of from a commercial point of view.

In particular, a so-called solar collector system has prevailed, with one here between so-called flat collectors and the aforementioned concentrating collectors.

In the case of flat-plate collectors, the basic structure is essentially always the same the same. This is where a mostly metal, usually flat body with a radiation-absorbing surface is used Mistake. This surface usually consists of black lacquer or similar material. Trapped in this body or there are conduits or ducts in

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which circulates a heat exchange medium that carries away the heat trapped by the absorbent surface. This heat can then be used directly or indirectly for heating purposes.

Since, according to the Stefan-Boltzmann law, every black body also emits a thermal radiation, the intensity of which increases to the fourth power of its temperature, the collectors become covered with one or more layers of glass or plastic. These glass or plastic layers are for the wavelength range the rays emitted by the collector are not transparent, so that the partially reflected rays for the most part be absorbed by these glass or plastic layers and converted into heat there. This creates the so-called greenhouse effect.

The back of the collector is provided with a sufficiently thick insulation layer so that only very low losses here can arise.

In order to make the relationship between absorption and emission more favorable, in the case of improved flat-plate collectors, instead of the a so-called selective surface is applied to the black surface. Selective surfaces have the advantage that the

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Solar radiation is absorbed very well, but the emission is very low.

Flat-plate collectors have a number of advantages. In this way, they can also convert diffuse radiation into thermal energy. Next there is a high degree of efficiency to 6O ⁰ C heating medium. Furthermore, flat-plate collectors are relatively inexpensive and easy to assemble.

disadvantage

But some of the flat-plate collectors should also be mentioned. In particular, the poor efficiency at high temperatures, temperatures are hard on 10O ⁰ C to achieve. Even if the collectors are optimally aligned with the sun, i.e. at midday, the reflection from the flat cover panes is particularly large in the morning and in the evening due to the very oblique angle of incidence of the rays. This reduces the efficiency. Since, except at night, heating energy is required especially in the morning and in the evening, this is precisely what is very disadvantageous. Furthermore, it is very difficult to seal the space between the collector and the cover layer in an airtight manner. Often moist air gets into this cavity and causes the glass panes to fog up. This reduces the efficiency. A vacuum as high as possible in this cavity would be ideal. Because of the relatively large surfaces, however, a slight vacuum is likely to break the glass.

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break in ben. In order to achieve good efficiency, the collector surface must be aligned as precisely as possible to the mean position of the sun. On roofs that do not have this optimal position and inclination by chance, the assembly is problematic or the efficiency is very poor. A sail-shaped installation of the collectors is unlikely to be approved for several reasons. Since the collectors in the Usually only produced in certain sizes, they are difficult to adapt to special roof shapes.

In the case of the above-mentioned concentrating solar collectors, the incident solar radiation is measured with the help of an optical arrangement, E.g. a mirror or lens system, focused on a point, a line or a surface. In the case of solar collectors for heating purposes As a rule, cylinder parabolic mirrors are used, in which the incident rays are concentrated on a line. Rotationally symmetrical parabolic mirrors are rarer.

The cylinder parabolic mirrors are mostly made of glass with a thin layer of silver applied to the back. The incident Rays are reflected by this layer onto the focal line of the parabolic mirror.

In another variant, the parabolic mirror consists of high-

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polished metal.

The absorber is located in the focal line of this Parablo mirror. These are usually black metal pipes or glass-coated black metal pipes, as well as glass pipes with black Liquid that is used as a heat transfer medium at the same time or special metal profiles that are made of a glass tube be enclosed. Furthermore, several glass tubes pushed into one another are also conceivable, one of which has a selective one Absorber coating is provided and the underlying glass tube as an inlet and outlet pipe for the heat transfer medium serves.

An essential feature of the concentrating collectors is the concentration factor. This factor C forms the ratio from the entry surface of the collector to the surface of the absorber. The larger the factor C, the hotter the carrier medium can be be heated.

The advantages of concentrating collectors include that, depending on the concentration factor, very high temperatures can be reached can. In the case of indirect further use, the level of the temperature is a measure of good efficiency. Advantageous is also that because of the small absorber surface

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emission and convection losses are significantly lower compared to the entry surface than with flat-plate collectors.

The disadvantage is that concentrating collectors only work in direct sunlight. So you need the sun be tracked, which requires an additional mechanism. Furthermore, these are more complex to maintain and can only be accessed particularly suitable roofs. These are preferably flat roofs. On sloping house roofs, assembly is very problematic. Another disadvantage is their sensitivity to wind pressure. They are also relatively expensive and, because of their standardized sizes, cannot be varied at will and are not good at them can be individually adapted to special requirements.

It is now the object of the present invention to provide a collector arrangement to create at least the most essential advantages of flat-plate collectors and concentrating collectors while avoiding their disadvantages combined and which in particular are easy to manufacture and extremely inexpensive is and should have a wide range of applications.

According to the invention, this is achieved in that the collector elements are bottle-like hollow bodies made of glass or plastic, which are placed next to each other in any number on a tube

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can be pushed on and braced against one another at their end faces, the jacket of the respective hollow body with the tube Distance surrounds.

Here, such a collector element can now have a neck and a base with an opening, which the latter is suitable is to take up the neck of another hollow body in a pluggable manner.

The opening in the floor can be used for sufficient stability be limited by a retracted ring flange.

This could expediently such collector elements on a extremely inexpensive way after a bottle manufacturing process be made in a glassworks.

The design of a collector arrangement is then preferably such that a plurality of tubes, each of which has a plurality of collector elements carry, parallel to each other with a distance that corresponds approximately to the largest width of a collector element, arranged and adjacent pipe ends are connected to one another by elastic elbows or hoses, then one An expedient further development can be such that the parallel pipes carrying collector elements are connected to one another in an articulated manner to form a louvre-like arrangement.

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For example, embodiments of the subject matter of the invention are explained in more detail below with reference to the drawing.

Show it:

Fig. 1 is a schematic representation of a solar energy heating system ;

2 shows a collector element in longitudinal and cross-section

FIG. 3 one of several collector elements according to FIG. 2
and collector assembly composed of pipes
for a heating system according to FIG. 1, in plan view and
in side view; and

4 to 7 different examples of use of collector arrangements according to Fig. 3.

In the solar energy heating system illustrated schematically in Fig. 1, water is heated as a heat exchange medium in a collector arrangement 10, preferably mounted on the roof of a house, under the action of the sun and then a consumer 11 in the form of a heater via a flow line 13 fed. In this system, the water flow is through a circulation pump 12 in the return line 14 of the

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Circulatory system driven.

At this point it should be mentioned that in this way, of course, a plurality of additional consumers are connected in the system can, whereby the consumers can also be of different types. Hot water boilers, for example, are also used as consumers and swimming pools in particular.

One for such a previously described solar energy heating system particularly suitable collector arrangement 10 is shown in FIGS. 7 and will be explained in more detail below.

An essential feature of such a collector arrangement are collector elements, which are formed here by bottle-like hollow bodies 15 are formed from glass or plastic, as shown in particular in FIG. 2 and in any number next to one another a tube 16 can be pushed out. Each of these hollow bodies 15 has a neck 17, the inner diameter of which corresponds to the tube 16. The outside diameter of the neck 17, on the other hand, corresponds to the clear width of an opening in the bottom 18 of the hollow body 15,

There is enough play in such a way that the neck 17 can be inserted into the opening in the bottom 18 of another hollow body 15. The base opening is delimited by a drawn-in annular flange 19 for sufficient stability. Both in the bottom 18 and on the jacket

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of the neck 17 sind.Ringnuten 20 and 21, respectively, attached to the receptacle serve as a sealing compound or a sealing ring.

Any number of said hollow bodies 15 can now be pushed onto a correspondingly long tube 16 and onto it by means of flange means that can be screwed onto the pipe ends, for example 22 (Fig. 3) brace each other, so that a closed system is created, such that the hollow body 15 the pipe Enclose 16 as a continuous glass jacket, the glass jacket surrounding the tube at a distance.

As the cross-sectional view in Fig. 2 further shows, the Jacket of the bottle-shaped collector element 15 in a back 115 representing and divided into a half representing a front side 215, the rear side 115 having a reflective layer 23, is preferably coated with a silver layer. Because of this coating, the rear side 115 acts as a mirror. One A further improvement in efficiency can also be achieved by mirroring the two end faces.

In the cross section according to FIG. 2, the jacket of the bottle-shaped collector element 15 can now have the most varied of shapes. For example , both lateral surfaces can be semicircular in cross-section. Preferably, however, the front side 215 will have a semicircular shape in cross section and the rear side 115 will have a substantially or at least partially parabolic shape in cross section. ;

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So that the mirror coating is not damaged by the weather can be, this is additionally covered with a cover layer, e.g. made of aging and weather-resistant plastic, or sealed. This plastic layer also serves as an insulation layer.

Depending on the size of the hollow body 15 and the diameter of the pipe 16 can thus achieve a desired concentration factor will. It goes without saying that the tube 16 is approximately in the focal line of the rear side forming a mirror 115 should be appropriate. Because of the relatively large diameter of the tube compared to the opening area, the tube can however, they can be attached relatively imprecisely. Even in the variant in which the rear 115 is for the sake of simplicity also only has a round surface, for this reason the tube should still have almost all of the reflected rays catch.

Another variant for the reflection of rays can be seen in an elastic shield with a reflective coating, which, when pressed together, can be inserted into the collector elements, whereupon the shield can be opened in the relevant Fixed element.

As FIG. 3 shows in particular, a collector arrangement is now formed in that a plurality of tubes 16, each with one A plurality of collector elements 15 carry, parallel to one another, preferably at a distance that is approximately the greatest width of a

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Collector element 15 corresponds, arranged and adjacent pipe ends by pipe elbow 24 or elastic hoses together get connected. This generally two-dimensional structure then has a continuous pipe system with a connection 113 for the flow line 13 and a connection 114 for the return line 14 in Fig. 1. These measures make it possible to Assemble collector arrangements that can be adapted to practically any roof shape and above have additional areas of application, as will be explained in more detail below.

Not just any size and adaptability to any roof shape can be achieved. Under architectural and aesthetic aspects, a multitude of different shapes can also be used are composed of collectors. In this way, mosaic, star, circular shapes, etc. can be implemented. This should also be the case in general Strive to match individual designs.

This system offers another major advantage for houses whose roofs are not in an optimal position to the sun by chance. In this case, the collectors are also mounted side by side and flat on the corresponding roof, by simply rotating the opening plane of the individual collector elements 15 around the pipe axis in the direction of the central position of the sun

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However, efficiency can be increased significantly (Fig. 4). In addition, the curved surface of the hollow body also Inclined rays can be absorbed much better than, for example, with flat-plate collectors.

As practice shows, because of the flat angles of incidence in flat-plate collectors, the efficiency in the morning and in the evening is relative bad. And it is precisely then, except at night, that a particularly large amount of heating energy is required.

With the proposed system, this disadvantage can be largely eliminated by adding a specific one according to FIG Number of collector elements 15 aligns more in one direction or the other. Here too, the arched, sun-side halves 215 of the hollow body 15 inclined rays are absorbed much better. Through this a more even temperature profile can be achieved throughout the day.

Another significant advantage of the proposed system over the conventional systems is when it comes to mounting To achieve flat roofs. While both the flat plate collector and the concentrating collector protrude from the roof surface must be aligned to the sun, can after the new

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System the individual collector elements are laid flat on the roof like an additional second roof skin, and only the opening levels of the individual collector elements would have to be aligned with the mean position of the sun by rotating around the pipe axis will.

Another advantage of the above-described arrangement is that this collector arrangement can also be used on vertical house or other wall walls facing the sun can also be usefully attached (Fig. 6). The collector units in this case are advantageously parallel to the earth's surface aligned, and the opening levels aligned to the mean position of the sun by rotating around the pipe axis. Here, too, this arrangement should act like an additional wall and, in addition to general weather protection, also as an additional wall Act as thermal insulation.

In a corresponding arrangement, these collector arrangements could in this form can even be designed as garden fencing or the like.

Another possible application is shown in the Fig. 7, in the parallel arrangement softer collector, the collector elements 15 supporting tubes 16 articulated to each other in such a manner comparable

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are bound that they form a blind-like arrangement. In the example shown, this blind is also used for Covering a swimming pool 100 and can be moved in a suitable manner into a corresponding chamber 101 or out of this be extended. The articulated connections between the individual tubes can be screwed joints or links be a chain.

A decisive advantage of the collector arrangement described above lies in the fact that these are both the most essential features of a flat-plate collector and those of a concentrating collector Has collector. So, depending on the ratio of the opening plane to the diameter of the power pipe, a predetermined one Concentration factor can be achieved so that higher temperatures can be achieved than with flat-plate collectors. In addition, a high proportion of diffuse radiation energy can be captured and converted into thermal energy.

Furthermore, such a collector arrangement can be designed to be very weather and aging resistant. In addition, the air can are sucked out of the cavity between the tube and the hollow body, and a vacuum that is advantageous in each case can be built up. Furthermore, such a collector arrangement can be expanded or modified in the simplest possible way at any time. this

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seems particularly important because the requirements for a heating system can change at any time. In addition, all components can be Manufacture this arrangement very well in advantageous standard sizes, which can also be done by non-experts in the "do-it-yourself" method can be put together. From the cost side, this is likely to be particularly beneficial for private homeowners Be interested. But even if you are undecided, a simple experiment you can carry out yourself should make the decision facilitate, whereby, as mentioned, the cost is very low. This should be particularly beneficial in the introductory phase impact. The individual components could thus also be sold via "do-it-yourself" chains and large mail order houses will. This could immediately attract a much larger group of buyers be addressed.

In the case of using glass for the collector elements you can this extremely cost-saving easily after a customary bottle manufacturing processes take place in a glassworks.

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Claims (12)

Claims S ₁ I / collector arrangement for a solar energy heating system, in which a plurality of collector elements interact with tubes serving to flow through a heat exchange medium, characterized in that the collector elements (15) are bottle-like hollow bodies made of glass or plastic, which Any number of them can be pushed next to one another onto a tube (16) and can be braced against one another at their end faces, the jacket of the respective hollow body (15) surrounding the tube (16) at a distance. 2. Collector element for a collector arrangement, characterized by a bottle-like hollow body (15) made of glass or plastic, with a neck (17) and with a base (18) with an opening, the clear dimension of which is designed, around the neck (17) a hollow body pluggable with play. 3. collector element according to claim 2, characterized in that the opening in the bottom (18) is limited by a drawn-in annular flange (19). 4. Collector element according to claim 2, characterized in that the clear width of the neck (17) corresponds to the diameter of a pipe 909816/0600 _0RIGlNAL inspected (16) corresponds to which a plurality of the collector elements (15) can be plugged. 5. collector element according to claim 2, characterized in that its jacket is divided into a rear (115) showing and a front (215) showing half, wherein at least the rear side (115) is coated with a reflective layer (23), preferably a silver layer. 6. collector element according to claim 2, characterized in that a sign with a reflective coating in the collector element is used and fixed by bracing. 7. collector element according to claim 5 or 6, characterized in that that both jacket halves are semicircular in cross-section. 8. collector element according to claim 5 or 6, characterized in that that the front side (215) is semicircular in cross section and the rear side (115) is at least partially in cross section have a parabolic shape. 9. A method for producing a collector element according to claim 2, characterized in that the production takes place according to a bottle manufacturing process in a glassworks. 909816/0600 10. collector arrangement according to claim 1, characterized in that that a plurality of tubes (16), each carrying a plurality of collector elements (15), parallel to one another at a distance, which corresponds roughly to the greatest width of a collector element, arranged and adjacent pipe ends are connected to one another by pipe elbows (24> or elastic hoses. 11. Collector arrangement according to claim 10, characterized in that the parallel pipes carrying collector elements are articulated are interconnected to form a louvre-like arrangement. 12. Use of the collector arrangement according to one or more of the preceding claims on a solar energy heating system with one or more consumers (11). 909818/0800